Dust controls attempt to curb air pollution in Imperial County, Calif.

And that fallowed land is having a secondary effect -- one that local activists and researchers fear could only aggravate the respiratory problems of people living in this area.

Much of the water that flows into the nearby Salton Sea comes from agricultural runoff, but that volume is on the decline because that water is being diverted from fields to urban areas to the west.

The expansive Salton Sea is evaporating at a stunning pace, exposing wide areas of pesticide-laced seabed to those strong desert winds.

“The impact of this exposed sea bed and the dust clouds that could accumulate are going to just sweep through this valley as though it was just leaves on the ground,” said Luis Olmedo, a local environmental activist.

He drove me along the main road that cuts through the several small cities that make up the Imperial Valley, pointing out the various sources of air pollution he feels are aggravating this area’s asthma problem.

There’s the fallow land, the burning of agricultural fields, the pesticide use, unpaved roads, and the popularity of off-road vehicles.

The county has settled with the EPA, and is now in the process of revising those rules. It plans to add further controls, like requiring farmers to better manage their fallowed fields and placing limits on the use of unpaved roads that kick up dust.

“We’re very confident that we’ll be able to bring cleaner air to our locals,” said Reyes Romero, an air pollution control officer for the county.

In the meantime, the residents of the Imperial Valley develop novel ways of coping with the poor air quality.

Photo by Adrian Florido

An indoor playground in Imperial County, Calif.

On a scorching 110-degree day in the city of Imperial recently, about a dozen kids were running around an indoor playground.

“I wanted to create a kind of indoor facility where we could control the climate a little bit, but also be able to provide a dustless facility,” said Rosie Nava, who founded The Family Treehouse.

The air conditioning is a big draw. But for Nava, more important is keeping this place free of dust.

“It is sanitized and disinfected every day. We clean for four hours,” she said.

Luis Velez, Luis Olmedo’s fifth-grade son, said he sees the effects of the air pollution at his school every day.

“Yeah a lot of my friends have asthma and when it’s a windy day they have to stay inside,” he said. “And our nurse, she has a drawer like, full of inhalers and asthma treatments.”

Later that day, as Olmedo and I drove down the main road, we spotted a dust storm forming above an empty agricultural field.

The wind was so strong that it kicked up dirt all around us, so thick as too mostly obscure the view of a field on the other side of the road. The entire area was covered in a thick layer of dust.